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Assessment of the EU stress tests

Wenisch and Becker

The March 2011 accident at the Fukushima I nuclear power plant proved that highly unlikely incidents cannot be excluded. Contrary to accepted practice Probabilistic Safety Assessments (PSA) do not constitute a sufficient basis to declare a plant operation safe. Safety of nuclear power plants needs to be backed by deterministic assessments, which excludes initiating events and accident scenarios only if they are proven to be physically impossible.

Events at Fukushima compounded public mistrust towards nuclear power worldwide. In Europe, the European Commission welcomed a suggestion by the government of Austria to conduct stress tests at all nuclear power plants in the European Union. The EU nuclear safety regulators –ENSREG –took over this task. The tests were introduced to improve confi-dence in the safety of European nuclear power plants (NPPs). In particular, they should examine the consequences of earthquakes and floods, and the com-bination of events previously excluded. However, the tests would be limited in scope: safety features such as ageing or design faults would not be taken into account.

Assessment of stress tests
An assessment of the stress tests –by Antonia Wenisch and Oda Becker, commissioned by Greenpeace- is published recently: Critical Review of the EU Stress Test performed on Nuclear Power Plants. 

The EU stress tests are not a safety assessment of the European nuclear power plants. They represent a limited analysis of the vulnerability of such plants with respect to natural hazards. The accident scenarios are focused on external events: the quality of the struc-tures, systems and components and the degradation of the oldest nuclear power plants in Europe are not subject of the analysis. The peer review team did not consider all safety issues that could trigger or aggravate an accident situation (e.g. ageing, use of MOX fuel, safety culture).

The design of the plants with respect to natural events varies, therefore the safety margins can only be assessed through an engineering judgment. In December 2011, the IAEA has published a new guide for extreme weather hazards. Greenpeace recommends that all plants make an assessment of weather hazards according to the new IAEA guide.

Severe accident management, espe-cially regarding spent fuel pools and multi-unit accidents like at Fukushima, is an issue everywhere, but the way it is tackled varies immensely. Only one country (Slovenia) has a simulator for severe accident management.

The peer review team has not assessed the current safety level of the European nuclear power plants, but only the potential increase in the level of safety in the next decade. Currently, there are several known shortcomings with respect to the protection against earth-quake, flooding and extreme weather. Furthermore, it is well known that it will be impossible to cope with a severe accident,  especially if it is accompa-nied by earthquake or flooding. The reviewers only described the weaknes-ses they identified, but not an overall assessment of all facts, which would allow a risk

The EU stress tests have no direct effect on the European nuclear power plant fleet. ENSREG has no say on the lifetime extension applications of even the oldest plants with the most obvious problems (Mühleberg, Doel, Rivne etc.). To gain an accurate picture of nuclear risk, EU decision makers should add a third leg to the nuclear stress tests - a full assessment of emergency response preparedness, which examines the viability of emergency response plans, address weaknesses and purpose improvements.

Far from restoring faith in the safety of nuclear power in Europe, the stress tests and ENSREG report published in April 2012 serve to further undermine it. At their most basic level, nuclear plants are concrete shielding to a fission process that creates large quantities of energy. Energy Commissioner Oettinger has acknowledged that the elimination of risk at such facilities is impossible, with efforts limited to merely minimising the threat. Across Europe, the stress tests have revealed some unacceptable failures in risk management. Serious gaps have repeatedly been found in readiness for emergencies. No guarantee can be given that plants operating in earthquake zones will remain safe in the event of serious seismic activity. Many lack any form of safe containment for their spent fuel pools and some have entirely inadequate access to emer-gency power. In short, the lessons from Fukushima are clearly yet to be learned in Europe.

Yet some plants are located just 10 kilometres from major urban populations like the city of Antwerp, raising the question why evacuation plans were not considered as part of the stress tests. The tests also failed to consider the impacts of multiple disaster scenarios as experienced at Fukushima in 2011 - the very crisis that originally prompted the stress tests. On top of these questionable omissions, the test results are not standardized in any way, making comparisons effectively impossible. The results are lack of any kind of pass or fail criteria and the partiality of those carrying and vetting the tests and falls short of providing the relevant authori-ties with the necessary information to draw proper conclusions.

When EU heads of state and government meet in autumn 2012 to discuss the results of this exercise, they can only conclude that the stress tests and peer review fall far short of expectations. They should recognise that nuclear power will always remain a dangerous technology. This is why all European governments should develop a credible phaseout plan for nuclear power 
in Europe, starting with the most risky reactors.

Source: Critical Review of the EU Stress Test performed on Nuclear Power Plants. Study commissioned by Greenpeace. Authors: Antonia Wenisch, Oda Becker, May 2012 (Published 14 June 2012)
Both the full report and the executive summary are available at:
Ing. Antonia Wenisch, Mail: antonia.wenisch[at]
Dipl. Phys. Oda Becker, mail: oda. becker[at]

Status of stress tests nuclear power plants in EU

Nuclear Monitor Issue: 
Patricia Lorenz, FoEE

In reaction to the Fukushima nuclear disaster the European Union decided to start a process to make sure whether European Union nuclear power plants are safe and events like in Japan can be excluded in Europe. Stress tests are defined as: 'Reassessment of safety margins of nuclear power plants in the light of the events at Fukushima: extreme natural events challenging the plant safety functions and leading to severe accidents".

In a three step process all countries were to check their plants based on the ENSREG (European Nuclear Safety Regulators Group) criteria catalogue, which again is based mostly on WENRA (Western European Nuclear Regulators' Association) criteria. While the first is a legitimate body of all 27 EU nuclear regulators, WENRA is a only the club of nuclear regulators.

A major issue is transparency, often announced by the regulators and EU officials, but this did not trickle down to the regulators ye. WENRA did conduct an almost unnoticed public consultation on the criteria, but did not even acknowledge receiving contributions from the public, like e.g. fairly elaborate contributions by FOEE (Friends of the Earth Europe) or Greenpeace and other groups. Nothing was taken up, no reason given why not. The first part of the stress tests was finished in time, when in August all operators handed in the reports on their plants. Based on these, the regulator reports were made and published on the ENSREG homepage. The differences in methods, approaches and simply the number of pages of the reports, of course are substantial.

One of the most important lessons learnt from Fukushima is that the probabilistic approach is not reliable; events unlikely to happen according to models and codes used during designing, licensing and safety checks, were obviously proven wrong. This is reflected in the ENSREG paper, urging states to look into extreme natural events, like seismicity and flooding and their combinations.

A good example for business as usual is the Romanian report. For assessing the seismic risk they apply very weak criteria which are contradicting international practice. For earthquakes it would be necessary to look into a earthquake which have a return period of at least 10 000 years and use this data to prove that an NPP resists an earthquake. Instead the Romanian reports sticks with the old data and uses the 1000 years return period chosen as design basis. The Czech report with 7 pages only stands out by being of exceptionally poor quality; however, there is an understanding they will come up with more complete one in the next few weeks. Similar though the situation in the Netherlands, where the regulator so far did not receive much more than the overview over what the Borssele operator will send until October 31.

The Slovak reports went into a lot more length, but the key questions are not answered:  In case of a station black-out, when no emergency diesel generators are available, having time is a great advantage to restore power for starting up cooling pumps for removing residual heat from the reactor and cooling the spent fuel pool. The report does not show clearly, how long it is possible to keep the reactor in a safe state during severe accident measures without power. There is no prove provided on how external impacts like airplane crashes, fires, explosions can be excluded as direct hazards for the reactor buildings /containment systems, which could lead to core melt.

What is to happen next: The EU Commission and ENSREG will produce the first progress report based on the individual country reports for the EU Council meeting on December 9. This phase is followed by a unique new procedure: EU peer review, when teams will evaluate the reports and are expected to even look at the nuclear power plant site. This is something very new in nuclear safety, which is the field of national competence only. The exact conduct of those peer review is of course an issue of discussions. Currently it seems that there will be 17 peer review teams. 14 of them will be vertical (looking into all aspects - one per country) and 3 will be horizontal (looking at all countries but only one issue: earthquakes, floods, loss of power and ultimate heat sink). Coordination will be done by a supervisory board.

There are concerns about the role of Mr. Petr Krs from SUJB to head the peer review process. This leading role given to the Czech regulator is met with a lot of distrust and criticism from NGO in this field. SUJB is acting openly pro-nuclear in the domestic energy debate and there is a lot of criticism about SUJB's role in the welding case around Temelin and the national stress report.

Two major Fukushima issues are not looked into properly: the emergency preparedness in case of severe accidents in European plants and the security issues. While it is obvious, that evacuations are not possible in densely populated European countries, the issue of security threats like armed attacks and targeted airline crashes are hidden under the thick cover of confidentiality of interior ministries, secret services and similar institutions. Along those lines a European Council working group was formed and started its meetings:  The first meeting of this working group under the Atomic Question Group (ATO), called Group Ad Hoc on Nuclear Security (GAHNS) took place before the summer break. It can be seen as a success, that all EU Member States participated in this group, including UK and Czech Republic. The European Commission participates as an observer. Some information from this group is expected to be taken up in the Commission Reports to the Council in December, April and June. The group has prepared a long list of issues and questions to be addressed.

The peer review will last until mid-2012. During this phase several evaluating events are expected to take place. On the one hand NGOs will demand seminars to be held in their countries, which will be encouraged by the EU Commission. The European Economic and Social Committee (EESC) is organizing a conference in December in Brussels and in the Summer of 2012 ANCLI (the National Association of Local Information Committees) and the EU Commission will co-organize a major meeting on stress-tests and Aarhus Convention. For further information also concerning the broader context please read the article already published earlier in this publication.

Source: Patricia Lorenz (with information provided by Jan Haverkamp –Greenpeace International- and independent nuclear safety expert Antonia Wenisch, who contributed first evaluations of some of the country reports)
Contact: Patricia Lorenz
Mail: patricia.lorenz[at]

In brief

Nuclear Monitor Issue: 

Municipalities try to block Danish plans for a final LILW repository.
The five Danish municipalities that host the six sites designated by Danish Decommissioning (DD) as a potential final low- and intermediate-level radioactive waste repository (see In Brief, Nuclear Monitor 727, 27 May 2011) have all refused to host it. On 26 May they sent a letter to the Danish interior and health minister, Bertel Haarder, suggesting that Risø National Laboratory on the island of Zeeland, where almost all of the radioactive waste has been produced at three research reactors, should be the place, where the waste is kept in the future. If that is not possible, a deal should be struck to send the up to 10.000 cubic metre radioactive waste abroad to a country experienced in dealing with it. The municipalities were dissatisfied that they had not been consulted in advance and that they had to hear of DD’s recommendations through the press. The minister dismissed the protests, arguing that the decision where to place the waste is several years off in the future and that there would be plenty of time to discuss the final location. However, locating the waste will not be up to him because the Danish interior and health ministry that has so far overseen the process is expected to give up its responsibilities after the completion of the pre-feasibility studies that has now been submitted. Since 2009 three other ministries have been fighting each other in order not to have to take charge of the project. The whole process has been heavily criticised in the media as well as from political opposition parties. Most recently, the Swedish NGO Office for Nuclear Waste Review (MKG) has criticised DD for not acknowledging that some of the waste is high-level radioactive waste and that it has failed to distinguish between short and long lived intermediate-level radioactive waste. According to MKG, apart from being designed to store only the short lived low- and intermediate-level waste and not the long lived, the planned Danish repository does not live up to Swedish standards, mainly because the safety analysis is too short-term.
Ingeniøren, 29 March 2011 / Jyllandsposten, 15 April 2011 / Radio Denmark, 26 May 2011

Sit-in against Jordan nuclear program in capital Amman.
On May 31, Jordan wittnessed its first anti-nuclear action. Not a spectacle in terms of number of people and methods applied, the participants comprised many concerned Jordanian citizens who are worried of the highly dangerous potential impacts of nuclear energy in Jordan. It included people from various disciplines of life, connected with their fear about the country’s nuclear program, which calls for the establishment of a 1,000 megawatt (MW) nuclear reactor. Wearing black T-shirts reading “No to a nuclear reactor”, the 40 protesters expressed concern over the effects of a nuclear reactor and uranium mining on public health and the environment.

Basil Burgan, an anti-nuclear activist and part of a coalition of 16 NGOs, said the demonstration was the “continuation” of efforts to take Jordan’s nuclear ambitions off-line. “We have come to a point where nuclear power has begun to take priority over solar and wind energy and we want to say that a small desert county like Jordan has no need for a nuclear power program,” he said on the sidelines of the sit-in,

Adnan Marajdeh, a resident of the Hashemiyyeh District near the planned site of the country’s first reactor in Balama, some 40 kilometers northwest of the capital, said there has been growing concern among local residents over the social and environmental impact of the plant. “We already suffer from the effects of the Samra Power Station, the Khirbet Al Samra Plant, a steel factory… now they have to put a nuclear power plant on top of us as well?” added the military retiree, who is president of the Jordan Environment Protection and Prevention Society.

Despite a resurgent opposition to nuclear power, Jordan is expected to select one of three short-listed vendors - Canadian, Russian and French-Japanese technologies - by June 30 for the construction of the countries first nuclear power plant.
Jordan Times, 1 June 2011 / Blog Batir Wardam at:

UK: No stress-test for Sellafield.
Media reports early June cited a British government spokesperson as saying that Sellafield would not be one of the 143 nuclear reactors across Europe to undergo a “stress test”. The spokesperson explained that the UK decision was based on the fact that Sellafield was a nuclear processing facility and not a power plant, therefore it did not meet the EU criteria for stress-testing. But Sellafield’s exclusion causes Irish consternation and the "renewed goodwill and neighbourliness between Ireland and Britain that has followed Queen Elizabeth’s successful visit to these shores" is facing fresh peril.

The Irish government do not seem to be taking no for an answer - a spokesperson for Environment Minister Phil Hogan said it was the department’s “understanding and expectation” that the stress test would apply to Sellafield, following a bilateral meeting on the issue in March.

“Sellafield cannot be exempted from vital safety health checks because of a technicality. It remains an active nuclear site and therefore poses risks like any other. The UK authorities should be willing to put Sellafield to the stress test, even if it’s not covered by the EU proposal, as it still represents a major safety concern for Irish citizens,” said the Fine Gael MEP Mairead McGuinness., 4 June 2011

EU: directive to export radioactive waste.
EU member states should be able to send their radioactive waste to non-EU countries according to the EU Energy Committee. Voting on a draft directive on the  management of spent fuel, MEPs agreed that countries should be able to export radioactive waste outside of Europe, as long as it is processed in accordance with new EU safety rules.

Under the proposed directive, each EU state must create programs to ensure that spent fuel and waste is "safely processed and disposed of", as well as holding plans for the management of all nuclear facilities, even after they close.

MEPs also backed stricter rules for the protection and training of workers in the industry, agreeing that national governments must ensure sufficient funds are available to cover expenses related to decommissioning and management of radioactive waste under the "polluter pays" principle.

The EU Parliament's final vote on the directive will take place in June., 27 May 2011

Albania moves away from nuclear.
Maybe it was unlikely already but Albania moved one step away from nuclear. Albanian Premier Sali Berisha hinted May 7, on the fifth anniversary of the European Fund for Southeast Europe that the country is reconsidering previous plans for the construction of a nuclear power plant. Despite not declaring a definitive step down from the project, Albania’s Prime Minister made reference to the incident at Fukushima and Germany’s decision to close all nuclear plants by 2022 as a sign his government might be moving away from plans to build a nuclear plant. At the same time, according to a report by Top Channel, Berisha asked EFSE to help provide loans to investors willing to build new hydropower plants, meaning that for the time being Albania’s priority will be water generated energy., 8 June 2011

France: only 22 % in favor of new reactors.
France is the world's most nuclear-dependent country, producing 80 percent of its power from 58 reactors, but public opposition is growing. An opinion poll published June 4, found just over three-quarters of those surveyed back a gradual withdrawal over the next 25 to 30 years from nuclear technology.

The Ifop survey found only 22 percent of respondents supported building new nuclear power stations,15 percent backed a swift decommissioning and 62 percent a gradual one.
Reuters, 7 June 2011

Little stress with stress test

Nuclear Monitor Issue: 
Patricia Lorenz, FoEE/Global 2000

The stress tests for European Union (EU) nuclear power plants were suggested by the Austrian Minster for the Environment right after the Fukushima disaster, without concrete ideas how they should be performed. The idea was quickly adopted by Brussels and hijacked by the nuclear establishment, namely WENRA. Stress tests are defined as: "Reassessment of safety margins of nuclear power plants in the light of the events at Fukushima: extreme natural events challenging the plant safety functions and leading to severe accidents.”

The Western European Nuclear Regulators' Association (WENRA) outlined a proposal, which was put up for public commenting until May 5. Slightly more resistance than expected became visible in the run-up to agreeing on the WENRA stress test outline by EU member states: ENSREG, created in 2007, the until this point hardly known Group nuclear regulators (European Nuclear Safety Regulators Group) represents also the non-nuclear EU-27 countries. In ENSREG, some countries, mainly Austria and Germany, did not accept the WENRA suggestions and asked for much more stringent testing - with out-spoken support by EU Commissioner Oettinger, wanted more stringent stress test. However, the operator countries tried to stay in the usual routine of testing– under the political leadership of UK and France.

Negotiations were really tough, especially the EU Commission warned that negotiations might break down and no stress test and nothing similar would be achieved. The compromise was presented on May 25. (see box: EC-Memo)

Yes:  plane crash will be included in the tests – but only in an implicit manner

No: Terror is not a task of majority of ENSREG regulators, therefore terror attacks cannot be included. This matter will be discussed with the Council to determine who is responsible (intelligence, police etc.).

This part of the stress test is really not clear, it is a compromise, because Austria and Germany wanted to include air crashes, but the big nuclear countries are against. Therefore the robustness of nuclear power plants in case of external impacts are stressed regarding their ability to guarantee cooling and safe shut down (ultimate heat sink and power supply). An explosion near the plant or an air crash both challenges the structure of containment and other essential buildings directly or for example due to a fire. Severe accident management is stressed in all these events. In this context the robustness of structures, systems and components has to be proofed; weak points are to be identified and improvements should be proposed. Subject of the stress test is not the initiating event (air crash, flooding, explosion or fire) but the capability of the plant to maintain, control, safe shut down and core cooling without external support as long as necessary (the lesson from Fukushima: it could be weeks  to reclaim control over the nuclear power plant).

The Stress test is defined as: “Reassessment of safety margins of nuclear power plants in the light of the events at Fukushima: extreme natural events challenging the plant safety functions and leading to severe accidents.” (ENSREG Annex 1 EU 'Stress test' specification)

The stress test will be conducted in 3 phases:
-1: started already on June 1: the operators/utilities make a report based on stress test criteria
-2: until August 15 the reports of the operators will be submitted to the national regulators, they will review the reports until September
-3: September: the European part of the test starts; teams from member states conduct peer reviews, also in the field to check the reports of phase 1 and 2 as well as the nuclear power plants. Those teams will consist of different experts from national regulators and EU Commission experts.

The Council will receive the final report for 9 December meeting.  EU Commission might suggest measures on how to continue. Tests will be prolonged into 2012.

In addition: In mid June, the member states energy ministry representatives will invite the EU neighbouring countries (Switzerland, Russia, Ukraine, Armenia and Turkey) to join the stress test effort. Switzerland already presented the first stress test results, at the same time the Swiss government decided the phase-out.

The information which has to be prepared by the operator is listed in Annex 1:
* All natural disaster esp. earthquakes and floods, need to be reassessed, in terms of return period and severity;
* The evaluation methodology has to be described as well as the reasons for the chosen design basis; and a conclusion on the adequacy of the design basis.
* Combinations of those disasters should be included.
* Provisions to protect the plant against natural disasters
* Plant compliance with the current licensing basis

Evaluation of safety margins, weak points and provisions to improve the robustness are also to be specified; In the end assessment of the range of disaster severity the plant can withstand without losing confinement integrity.

The most important functions needed during any emergencies in a nuclear power plant should be secured: Availability of power supply, and heat removal must be evaluated regarding redundancy and diversity. The time power sources and water supply can operate without external support has to be assessed. Provisions to prolong this time and increase the robustness of the plant are to be indicated. An evaluation of robustness of essential structures, systems and components which are needed for severe accident management is also foreseen.

A lesson from Fukushima is not that not only one reactor, but several plus the spent fuel pools can be affected by a major (natural or man-made) disaster at the same time.

The set-up of the stress test as described above might lead to useful results. Reports of each phase will be made public. It will be crucial that the public stays involved and closely follows the process, because the stress-tests are voluntary and the extent and depth of testing will be determined by national regulators. Some of the regulators already made clear that they do not expect to go much further than their routine testing. The first one to state that was the ENSREG chairman Mr. Stritar who pointed out the regulators are continuously testing and improving nuclear safety in their countries, also the Czech regulator does not see much news, only admitted that the issue of flooding might have changed since the plants were designed and sited due to climate change.

A quick calculation of high-risk reactors – older than 30 years (44 reactors) or lack of containment (12 reactors) or situated in a seismic region (5 reactors) and the 6 BWRs – gives the number of 67 reactors out of the 143 to be tested in the EU.

Interesting detail: EU Commissioner Oettinger believes, that the EU Commission will be invited when planning of new NPP is on the table. However, Bulgaria already announced that the planned NPP Belene is not to be stress-tested. The EU Commission also announced that the safety directive will be updated soon.

EC- MEMO 11/339 of 25 May 2011:
“What will be assessed in the stress tests?
It will be assessed whether the nuclear power plant can withstand the effects of the following events:
1- Natural disasters: earthquakes, flooding, extreme cold, extreme heat, snow, ice, storms, tornados, heavy rain and other extreme natural conditions.
2- All man-made failures and actions. These accidents can be: air plan crashes and explosions close to nuclear power plants, whether caused by a gas container or an oil tanker approaching the plant, fire. Comparable damaging effects from terrorist attacks (air plane crash, explosives) are also covered.”

Source and contact: Patricia Lorenz, Antinuclear Campaigner, FoEE/Global 2000
Neustiftgasse 36, A-107- Vienna, Austria

Global 2000

No fake stress test!

Nuclear Monitor Issue: 
WISE Amsterdam

In the wake of Fukushima, European Union officials pledged to create stress tests for the 143 nuclear power plants in the EU, that would evaluate the threat posed by natural disasters, terrorism, cyberwar and human error. Now it turns out that that  nuclear regulators are unwilling to accept stricter scrutiny and the plans are likely to get watered down.

Western European nuclear regulators are now staunchly rejecting calls for rigorous tests, Süddeutsche Zeitung reported in its May 4 edition. The regulators reportedly stated in an internal paper that they would only agree to conduct stress tests involving natural disaster scenarios -- and not terrorist strikes or other manmade situations. Instead, they would agree to compose reports on potential threats that would be submitted to the European Commission in Brussels. Neither would independent nuclear experts be given access to the plants under the plan.

European Commission sources told the newspaper that France and Britain have led the efforts to oppose more stringent stress tests. With France's 59 plants and Britain's 19, the two operate the largest number of nuclear power plants of any countries in Europe. Government officials in Paris and London have already stated that they plan to rely more heavily on nuclear power in the future despite the Fukushima disaster. Officials in London also stated they would not publish the results of the stress tests, which are expected to be completed by December.

Such a stress tests will not give a comprehensive and transparent risk assessment of the European nuclear installations. If developed in such a way the stress tests will only serve as "alibi tests" so nuclear operators can continue their business-as usual.

On May 11, the European nuclear lobby organisation Foratom said that "Including terrorist attacks or cyber-attacks as stress-test criteria would mean the checks will take more time and authorities won't be able to make the results public." And continued: "Our feeling is that citizens in Europe are waiting for the results and we should announce them without delays. People don't want to make things political and it's

important to prove that nuclear plants in Europe are safe."

Or... people want results now - therefore we should not do stress tests, but simply tell them it's OK...., commented Greenpeace spokesperson Jan Haverkamp

We ask you to take urgent action on this issue! Put pressure on Commissioner Oettinger by writing him an E-Mail expressing your concern and protest. Your protest for a genuine stress test on nuclear power plants in Europe. Go to

Sources:; Der Spiegel, 5 May 2011; Bloomberg, 11 May 2011